This chapter presents the ISO/IEC MPEG-7 Multimedia Content description Interface Standard from the point of view of managing semantics in the context of multimedia applications. We describe the organisation and structure of the MPEG-7 Multimedia Description schemes which are metadata structures for describing and annotating multimedia content at several levels of granularity and abstraction. As we look at MPEG-7 semantic descriptions, we realise they provide a rich framework for static descriptions of content semantics. As content semantics evolves with interaction, the human user will have to compensate for the absence of detailed semantics that cannot be specified in advance. We explore the practical aspects of using these descriptions in the context of different applications and present some pros and cons from the point of view of managing multimedia semantics.